1. Field of the Invention
The present invention relates to a metal body antenna having loop type radiation elements which operates in a wideband in multiple bands and, more particularly, to a metal body antenna including the housing unit of a terminal and loop type radiation elements having a wideband characteristic in multiple bands, wherein the end part of the radiation element supplied with a signal from a feeding power port formed in the housing unit is connected to a ground and the applied signal is connected to the ground by loop coupling.
2. Description of Related Art
With the recent rapid development of a communication technology, the size and weight of a communication device are reduced and performance of a communication device is further increased.
In particular, most of smart phones are rapidly evolving from the existing second-generation and third-generation communication methods, such as global system for mobile communication (GSM), code division multiple access (CDMA), and wideband CDMA (WCDMA), to a fourth-generation communication method, such as long term evolution (LTE). Furthermore, various technologies, such as Bluetooth, global positioning system (GPS), and Wi-Fi, are integrated.
A single mobile communication terminal may use a plurality of antennas to support various communication methods, but a wideband (or broadband) antenna technology capable of implementing multiple bands using a single antenna has been developed because there is a difficulty in disposing the plurality of antennas within the limited size of the terminal.
The wideband antenna technology has been proposed as a method for supporting various communication bands through the design of an antenna having a wide bandwidth. It is however impossible to improve efficiency of all of bands while implementing multiple bands based on a wide bandwidth. Furthermore, the space in various parts may be disposed is insufficient within the terminal because a wide space is required for the antenna design.
As a method for solving such a problem, a technology in which a housing unit forming an external appearance of a terminal is made of metal and the housing unit operates as an antenna was developed.
If the technology in which the housing unit operates as the antenna as described above is used, a space within the terminal can be additionally secured, more various parts can be disposed in the terminal using the additional space, and a thin type terminal design is made possible.
More specifically, antenna technologies using the housing unit as an antenna, that is, an antenna using a conductive bezel, and a metal battery cover has a disadvantage in that they have a narrow bandwidth. Accordingly, additional technologies, such as a tubable antenna technology in order to support various communication bands, have been additionally applied.
Furthermore, several problems, such as a rise of a production cost attributable to the application of the tubable antenna technologies, an increase of the design period attributable to added parts, and a rise of power consumption, are accompanied.
Accordingly, there is an urgent need for an antenna design technology which can utilize a space within the terminal as much as possible and achieve a smaller size and has a wide bandwidth even without using an additional technology by forming the casing of a housing unit forming an external appearance of the terminal using a metal material so that the housing unit operates as an antenna.
In order to solve such conventional problems, Korean Patent No. 10-1609542 entitled “Metal-Body Antenna to Operating Wideband in a Multi-Band” was proposed.
As the terminal tends to become slim, the PCB area of the terminal recently tends to be designed by avoiding parts, such as a speaker and a battery. In such a case, an extension cable is required because the feeding power port 8a of an existing antenna deviates from the area of a PCB 2a as shown in FIG. 1a, and there is a difficulty in the antenna design. In order to supplement such a disadvantage, there is a need for an antenna design in which a feeding power port 8b shown in FIG. 1b is disposed within the area of a PCB 2b. 